DIGESTION VISIBLE TO THE EYE. 
387 
string. At the end of the Jirst half hour, it presented the same 
appearances as the piece in the vial ; but when Dr. Beaumont 
drew out the string at the end of an hour and a half \ the beef 
had been completely digested and disappeared, making a differ- 
ence of result in point of time nearly seven hours. In both, the 
solution began on the surface, and agitation accelerated its pro- 
gress by removing the external coating of chyme as fast as it was 
formed. \ 
“ To ascertain still more accurately the difference between 
natural and artificial digestion (the one in and the other out of 
the stomach), Dr. Beaumont put twelve drachms of recently- 
salted boiled beef into a vial, with the same number of drachms 
of fresh gastric juice obtained through the opening of the stomach 
after a fast of eighteen hours; and then placed it in a basin of 
water on a sand-bath, where he kept it at the heat of 100° 
Fahr., and continued to agitate it gently. Digestion soon com- 
menced, and progressed uniformly for about six hours, when it 
ceased. One-half of the meat was then dissolved, and the tex- 
ture of the remainder loosened and tender, — resembling the 
same kind of aliment when ejected from the stomach, partly 
digested, some hours after a meal, as frequently seen in cases of 
digestion. On weighing the undissolved portion which remained 
after all action had ceased, six drachms and twelve grains of the 
beef were found to have been digested by twelve drachms, or 
nearly double its weight, of gastric juice. It thus appears, that 
a given quantity of gastric fluid can digest only a relative pro- 
portion of meat ; so that, when more is eaten than what there is 
juice sufficient to dissolve, stomachic disorder must necessarily 
follow. In this latter case, Dr. Beaumont found that the addi- 
tion of fresh juice causes digestion to be resumed. 
“ To discover what influence would be exerted on food masti- 
cated, swallowed, and mixed with the gastric juice in the usual 
way, and then withdrawn from the stomach, Dr. Beaumont gave 
St. Martin an ordinary dinner of boiled salt beef, bread, potatoes, 
and turnips , with a gill of pure water for drink ; and twenty 
minutes afterwards drew off through the opening about a gill of 
the contents of the stomach into an open-mouthed vial. In this 
short space of time digestion had already commenced, thus 
negativing the common notion, that an hour elapses before it 
begins. The vial was now placed in a water-bath, at a tempera- 
ture of L00°, and continued there for five hours. Examined at 
the end of that time, the whole contents were found to be dis- 
solved. On then extracting an equal quantity of chyme from 
the stomach, and comparing with the solution in the vial, little 
difference was observable between them, except that the process 
